package com.online.college.common.util;

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/**
 * 日期工具类
 */

public class DateUtil {

	private final SimpleDateFormat format;

	public DateUtil(SimpleDateFormat format) {
		this.format = format;
	}

	public SimpleDateFormat getFormat() {
		return format;
	}

	// 紧凑型日期格式，也就是纯数字类型yyyyMMdd
	public static final DateUtil COMPAT = new DateUtil(new SimpleDateFormat("yyyyMMdd"));

	// 紧凑型日期格式，也就是纯数字类型yyyyMMdd
	public static final DateUtil COMPAT_FULL = new DateUtil(new SimpleDateFormat("yyyyMMddHHmmss"));

	// 常用日期格式，yyyy-MM-dd
	public static final DateUtil COMMON = new DateUtil(new SimpleDateFormat("yyyy-MM-dd"));
	public static final DateUtil COMMON_FULL = new DateUtil(new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"));

	// 使用斜线分隔的，西方多采用，yyyy/MM/dd
	public static final DateUtil SLASH = new DateUtil(new SimpleDateFormat("yyyy/MM/dd"));

	// 中文日期格式常用，yyyy年MM月dd日
	public static final DateUtil CHINESE = new DateUtil(new SimpleDateFormat("yyyy年MM月dd日"));
	public static final DateUtil CHINESE_FULL = new DateUtil(new SimpleDateFormat("yyyy年MM月dd日 HH时mm分ss秒"));

	/**
	 * 日期获取字符串
	 */
	public String getDateText(Date date) {
		return getFormat().format(date);
	}

	/**
	 * 字符串获取日期
	 * @throws ParseException
	 */
	public Date getTextDate(String text) throws ParseException {
		return getFormat().parse(text);
	}

	/**
	 * 日期获取字符串
	 */
	public static String getDateText(Date date, String format) {
		return new SimpleDateFormat(format).format(date);
	}

	/**
	 * 字符串获取日期
	 * @throws ParseException
	 */
	public static Date getTextDate(String dateText, String format) throws ParseException {
		return new SimpleDateFormat(format).parse(dateText);
	}

	/**
	 * 根据日期，返回其星期数，周一为1，周日为7
	 * @param date
	 * @return
	 */
	public static int getWeekDay(Date date) {
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		int w = calendar.get(Calendar.DAY_OF_WEEK);
		int ret;
		if (w == Calendar.SUNDAY)
			ret = 7;
		else
			ret = w - 1;
		return ret;
	}
	
	public static int getAge(Date birthday) {
		Calendar calendar = Calendar.getInstance();
		if (calendar.before(birthday)) {
			throw new IllegalArgumentException("出生时间大于当前时间!");
		}
		int yearNow = calendar.get(Calendar.YEAR);
		int monthNow = calendar.get(Calendar.MONTH) + 1;// 注意此处，如果不加1的话计算结果是错误的
		int dayOfMonthNow = calendar.get(Calendar.DAY_OF_MONTH);
		calendar.setTime(birthday);
		int yearBirth = calendar.get(Calendar.YEAR);
        int monthBirth = calendar.get(Calendar.MONTH);
        int dayOfMonthBirth = calendar.get(Calendar.DAY_OF_MONTH);
        int age = yearNow - yearBirth;
        if (monthNow < monthBirth ||(monthNow == monthBirth && dayOfMonthNow < dayOfMonthBirth)) {
        	age--;
        }
        return age;
        
	}
	

}
